The present invention relates to tape cartridges with lids such as a front lid and a back lid.
The tape cartridges with lids are used, e.g. in 8 mm video tape recorders (VTR). Referring to FIGS. 12-13, a known tape cartridge 101 includes a casing 105, a pair of tape reels 103, 104 rotatably accommodated therein and having a magnetic tape 102 wound, a front lid 107 rotatably mounted to the casing 105 through a shaft 108 for closing a tape loading space or pocket 106 thereof, and a back lid 109 rotatably mounted to the front lid 107 through a shaft 110. Referring to FIGS. 14-15, the back lid 109 has at an end a cam boss or back-lid posture control device 111 which is engaged with a cam groove 113 of a back-lid support 112 of the casing 105. When rotating the front lid 107 in the open or closed direction, the cam boss 111 of the back lid 109 is moved along the cam groove 113 of the casing 105 to open or close the back lid 109 together with the front lid 107.
The tape cartridge 101 is constructed such that as shown in FIG. 14, when closing the tape loading space 106 of the casing 105 by the front lid 107, a hood 109a of the back lid 109 shuts a back-lid opening 121 formed in the upper side of the casing 105, and a leg 109b of the back lid 109 which is positioned on the side of the back of the magnetic tape 102 in the tape loading space 106 cooperates with the inside of the front lid 107 to hold the magnetic tape 102 for protection thereof. On the other hand, as shown in FIG. 15, when opening the tape loading space 106 of the casing 105, the back lid 109 and the front lid 107 are placed on the upper side of the casing 105 to loadably expose the magnetic tape 102.
With the known tape cartridge 101, in order to obtain smooth sliding of the cam boss 111 in the cam groove 113 upon lid opening/closing operation, a predetermined clearance or play is needed between the outer side face of the cam boss 111 and the inner side face of the cam groove 113.
The clearance, which is indispensable for smooth sliding of the cam boss 111 in the cam groove 113, may cause rattling of the back lid 109, however. Referring to FIG. 16, with much rattling of the back lid 109, a casing-side end of the hood 109a of the back lid 109 projects from the back-lid opening 121 arranged on the upper side of the casing 105 (this phenomena is referred hereafter to as "projecting phenomena"), and engages with one end 201a of a cartridge compartment 201 of a VTR, resulting in impossible eject of the tape cartridge 101, etc. The projection of the back lid 109 occurs rarely when the tape cartridge 101 is supported with the hood 109a of the back lid 109 up, and often when the tape cartridge 101 is supported in the inclined way or with the hood 109a of the back lid 109a down.
It is, therefore, an object of the present invention to provide tape cartridges which allows restrained projection of the back lid.